Risk Of Total Knee Replacement Research Articles

Dual-energy X-ray absorptiometry derived knee shape may provide a useful imaging biomarker for predicting total knee replacement: Findings from a study of 37,843 people in UK Biobank

ObjectiveWe aimed to create an imaging biomarker for knee shape using knee dual-energy x-ray absorptiometry (DXA) scans and investigate its potential association with subsequent total knee replacement (TKR), independently of radiographic features of knee osteoarthritis and established risk factors. MethodsUsing a 129-point statistical shape model, knee shape (expressed as a B-score) and minimum joint space width (mJSW) of the medial joint compartment (binarized as above or below the first quartile) were derived. Osteophytes were manually graded in a subset of images and an overall score was assigned. Cox proportional hazards models were used to examine the associations of B-score, mJSW and osteophyte score with TKR risk, adjusting for age, sex, height and weight. ResultsThe analysis included 37,843 individuals (mean age 63.7 years). In adjusted models, B-score was associated with TKR: each unit increase in B-score, reflecting one standard deviation from the mean healthy shape, corresponded to a hazard ratio (HR) of 2.25 (2.08, 2.43), while a lower mJSW had a HR of 2.28 (1.88, 2.77). Among the 6719 images scored for osteophytes, mJSW was replaced by osteophyte score in the most strongly predictive model for TKR. In ROC analyses, a model combining B-score, osteophyte score, and demographics outperformed a model including demographics alone (AUC ​= ​0.87 vs 0.73). ConclusionsUsing statistical shape modelling, we derived a DXA-based imaging biomarker for knee shape that was associated with kOA progression. When combined with osteophytes and demographic data, this biomarker may help identify individuals at high risk of TKR, facilitating targeted interventions.

Effect of Intravenous Zoledronic Acid on Total Knee Replacement in Patients With Symptomatic Knee Osteoarthritis and Without Severe Joint Space Narrowing: A Prespecified Secondary Analysis of a Two-Year, Multicenter, Double-Blind, Placebo-Controlled Clinical Trial.

To determine the effect of zoledronic acid (ZA) on the risk of total knee replacement (TKR) in patients with symptomatic knee osteoarthritis and without severe joint space narrowing (JSN). We included 222 participants (mean age 62 years, 52% female) from the two-year Zoledronic Acid for Osteoarthritis Knee Pain trial (113 received 5 mg of ZA annually and 109 received placebo) conducted between November 2013 and October 2017. Primary TKR were identified until February 22, 2022. The effect of ZA on TKR risk was evaluated using Cox proportional hazard regression models. Because the treatment effect failed the proportional hazards assumption, a time-varying coefficients analysis for treatment was conducted by splitting the study into two periods (ie, within and after two years of randomization). Over a mean follow-up of seven years, 39% and 30% of participants had any TKR in the ZA and placebo groups, and 28% and 18% had TKR in the study knee, respectively. Use of ZA was associated with a higher risk of TKR in any knee (hazard ratio [HR] 4.2, 95% confidence interval [CI] 1.2-14.7) and showed a trend in the study knee (HR 6.8, 95%CI 0.9-53.9) during the trial. In the posttrial period, the risk of TKR was similar in the ZA and the placebo groups for any knee (HR 1.2, 95%CI 0.5-1.8) and the study knee (HR 1.4, 95%CI 0.5-2.2). These results suggest that ZA is not protective against TKR in patients with symptomatic knee osteoarthritis and without severe JSN.

Is diet related to osteoarthritis? A univariable and multivariable Mendelian randomization study that investigates 45 dietary habits and osteoarthritis.

Diet is a safe intervention for many chronic diseases as a modifiable lifestyle. However, the potential causal effect of many dietary intake habits on the risk of osteoarthritis has not been fully understood. The purpose of this study was to reveal the potential causal relationship of 45 genetically predicted dietary intakes with osteoarthritis and its subtypes. Data on 45 dietary intakes were obtained from the UK Biobank study of approximately 500,000 participants, and data on six osteoarthritis-related phenotypes were obtained from the Genetics of Osteoarthritis Consortium study of 826,690 participants. We performed univariable Mendelian randomization (MR), multivariable MR and linkage disequilibrium score regression (LDSC) analyses. In univariate analyses, 59 potential associations between diet and osteoarthritis were found. After false discovery rate (FDR) correction and sensitivity analyses, 23 reliable causal evidence were identified. In multivariate analyses, controlling separately for the effects of body mass index, total body bone mineral density, and smoking status, eight robust causal relationships remained: Muesli intake was negatively associated with knee osteoarthritis, spine osteoarthritis and total knee replacement. Dried fruit intake had a negative association with osteoarthritis of knee and total knee replacement. Eating cheese may reduce the risk of osteoarthritis in the knee and spine. And alcohol usually taken with meals was associated with a reduced risk of total knee replacement. LDSC analyses showed significant genetic correlations between all exposures and their corresponding outcomes, respectively, in these eight causal relationships. Evidence of dietary effects on osteoarthritis is provided in our study, which has important implications for the prevention, management, and intervention of osteoarthritis in common sites through rational dietary modification.

THE BURDEN OF END-STAGE OSTEOARTHRITIS IN AUSTRALIA: A POPULATION-BASED STUDY ON THE INCIDENCE OF TOTAL KNEE ARTHROPLASTY ATTRIBUTABLE TO OVERWEIGHT/OBESITY

To determine the risk of total knee replacement (TKR) for primary osteoarthritis (OA) associated with overweight/obesity in the Australian population.This population-based study analyzed 191,723 cases of TKR collected by the Australian Orthopaedic Association National Joint Registry and population data from the Australian Bureau of Statistics. The time-trend change in incidence of TKR relating to BMI was assessed between 2015-2018. The influence of obesity on the incidence of TKR in different age and gender groups was determined. The population attributable fraction (PAF) was then calculated to estimate the effect of obesity reduction on TKR incidence.The greatest increase in incidence of TKR was seen in patients from obese class III. The incidence rate ratio for having a TKR for obesity class III was 28.683 at those aged 18-54 years but was 2.029 at those aged >75 years. Females in obesity class III were 1.7 times more likely to undergo TKR compared to similarly classified males. The PAFs of TKR associated with overweight or obesity was 35%, estimating 12,156 cases of TKR attributable to obesity in 2018. The proportion of TKRs could be reduced by 20% if overweight and obese population move down one category.Obesity has resulted in a significant increase in the incidence of TKR in the youngest population in Australia. The impact of obesity is greatest in the young and the female population. Effective strategies to reduce the national obese population could potentially reduce 35% of the TKR, with over 10,000 cases being avoided.

Metformin use and associated risk of total joint replacement in patients with type 2 diabetes: a population-based matched cohort study.

It is uncertain whether metformin use is associated with reduced risk of joint replacement in patients with type 2 diabetes mellitus. We aimed to establish whether metformin use was associated with a reduced risk of total knee replacement (TKR) or total hip replacement (THR) among these patients. We selected patients with type 2 diabetes mellitus that was diagnosed between 2000 and 2012 from the Taiwan National Health Insurance Research Database. We used prescription time-distribution matching and propensity-score matching to balance potential confounders between metformin users and nonusers. We assessed the risks of TKR or THR using Cox proportional hazards regression. We included 20 347 participants who were not treated with metformin and 20 347 who were treated with metformin, for a total of 40 694 participants (mean age 63 yr, standard deviation 11 yr; 49.8% were women) after prescription time-distribution matching. Compared with participants who did not use metformin, those who used metformin had lower risks of TKR or THR (adjusted hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.60-0.81 for TKR or THR; adjusted HR 0.71, 95% CI 0.61-0.84 for TKR; adjusted HR 0.61, 95% CI 0.41-0.92 for THR) after adjustment for covariates. Propensity-score matching analyses (10 163 participants not treated with metformin v. 10 163 treated with metformin) and sensitivity analyses using inverse probability of treatment weighting and competing risk regression showed similar results. Metformin use in patients with type 2 diabetes mellitus was associated with a significantly reduced risk of total joint replacement. Randomized controlled clinical trials in patients with osteoarthritis are warranted to determine whether metformin is effective in decreasing the need for joint replacement.

Increased Risk of Common Orthopedic Surgeries for Patients with Rheumatic Diseases in Taiwan.

Background and Objectives: Rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, psoriasis, and systemic lupus erythematosus (SLE), are characterized by chronic arthritis or spondyloarthritis, which can lead to joint and spine destruction. Our previous studies showed that the risk of common orthopedic surgeries, including total knee replacement (TKR), total hip replacement (THR), or spine surgery, was increased in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. The aim of this review was to summarize the risk of TKR, THR, cervical spine, and lumbar spine surgery on the basis of studies conducted using data from Taiwan's National Health Insurance Research Database (NHIRD). Materials and Methods: The risk of TKR, THR, cervical spine surgery, and lumbar spine surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE was summarized from the results of our previous studies and unpublished findings based on NHIRD data. Results: Patients with rheumatoid arthritis and psoriasis and men with ankylosing spondylitis showed an increased risk of TKR. Patients with rheumatoid arthritis, ankylosing spondylitis, and women with SLE showed an increased risk of receiving THR. Only patients with ankylosing spondylitis had an increased risk of cervical spine surgery, and patients with rheumatoid arthritis or ankylosing spondylitis showed an increased risk of lumbar spine surgery. Although the risk of THR, TKR, or spine surgery in these patients has declined in the era of biologics use, direct evidence for the effects of biologics agents is not yet available. Conclusions: There was an increased risk of common orthopedic surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. Clinicians should be vigilant to reduce the increased risk of TKR and THR in young and middle-aged patients with rheumatoid arthritis, THR in young patients with ankylosing spondylitis, and young female patients with SLE, as well as cervical spine surgery in young patients with ankylosing spondylitis.

Metformin use and the risk of total knee replacement among diabetic patients: a propensity-score-matched retrospective cohort study

Metformin has been shown to modulate meta-inflammation, an important pathogenesis in knee osteoarthritis (OA). The study aimed to test the association between regular metformin use with total knee replacement (TKR) in patients with diabetes. This is a retrospective study with electronic records retrieved in Hong Kong public primary care. Patients with diabetes aged ≥ 45 who visited during 2007 to 2010, were followed up for a four-year period from 2011 to 2014 to determine the incidence of TKR. Propensity score matching based on age, sex, co-medications and chronic conditions was conducted to adjust for confounding. Cox regression was implemented to examine the association between metformin use and TKR. In total, 196,930 patients were eligible and 93,330 regular metformin users (defined as ≥ 4 prescriptions over the previous year) and non-users were matched. Among 46,665 regular users, 184 TKRs were conducted, 17.1% fewer than that among non-users. Cox regression showed that regular metformin users had a 19%-lower hazard of TKR [hazard ratio (HR) = 0.81, 95% confidence interval: 0.67 to 0.98, P = 0.033], with a dose–response relationship. Findings suggest a potential protective effect of metformin on knee OA progression and later TKR incidence among diabetic patients.

Do Glucocorticoid Injections Increase the Risk of Knee Osteoarthritis Progression Over 5 Years?

Recent findings have demonstrated that intraarticular (IA) glucocorticoid injections can be deleterious for knees with osteoarthritis (OA). This study was undertaken to assess, in a real-life setting, the risk of knee OA progression in patients who received IA glucocorticoid injections over a 5-year follow-up period. We used marginal structural modeling with inverse probability of treatment weighting to determine the causal association between IA glucocorticoid injections and the 5-year risk of disease progression in patients with symptomatic knee OA from the Knee and Hip Osteoarthritis Long-term Assessment cohort. OA progression was defined as an incident total knee replacement (TKR) and/or radiographic worsening (Kellgren/Lawrence [K/L] grade or joint space narrowing [JSN]). We also examined these outcomes in knees that received IA hyaluronan (IAHA) injections. Among the 564 patients with knee OA included in the study sample, 51 (9.0%) and 99 (17.5%) received IA glucocorticoid or IAHA injections, respectively, and 414 (63.1%) did not receive any injection during follow-up. Compared to untreated knees, those treated with IA glucocorticoid injections had a similar risk of incident TKR (hazard ratio [HR] 0.92 [95% confidence interval (95% CI) 0.20, 4.14]; P = 0.91) or K/L grade worsening (HR 1.33 [95% CI 0.64, 2.79]; P = 0.44). IAHA injections had no effect on the risk of TKR (HR 0.81 [95% CI 0.14, 4.63]; P = 0.81) or K/L grade worsening (HR 1.36 [95% CI 0.85, 2.17]; P = 0.20). Similar results were obtained for JSN, and when TKR and radiographic outcomes were combined. In this study, IA glucocorticoid injections for symptomatic knee OA did not significantly increase the 5-year risk of incident TKR or radiographic worsening. These findings should be interpreted cautiously and replicated in other cohorts.

Developing and internally validating a prediction model for total knee replacement surgery in patients with osteoarthritis

ObjectiveThe objective of this study was to develop and internally validate a clinical algorithm for use in general practice that predicts the probability of total knee replacement (TKR) surgery within the next five years for patients with osteoarthritis. The purpose of the model is to encourage early uptake of first-line treatment strategies in patients likely to undergo TKR and to provide a cohort for the development and testing of novel interventions that prevent or delay the progression to TKR. MethodElectronic health records (EHRs) from 201,462 patients with osteoarthritis aged 45 years and over from 483 general practices across Australia were linked with records from the Australian Orthopaedic Association National Joint Replacement Registry and the National Death Index. A Fine and Gray competing risk prediction model was developed using these data to predict the risk of TKR within the next five years. ResultsDuring a follow-up time of 5 years, 15,979 (7.9%) patients underwent TKR and 13,873 (6.9%) died. Predictors included in the final algorithm were age, previous knee replacement, knee surgery (other than TKR), prescribing of osteoarthritis medication in the 12 months prior, comorbidity count and diagnosis of a mental health condition. Optimism corrected model discrimination was 0.67 (95% CI: 0.66 to 0.67) and model calibration acceptable. ConclusionThe model has the potential to reduce some of the economic burden associated with TKR in Australia. External validation and further optimisation of the algorithm will be carried out prior to implementation within Australian general practice EHR systems.

Prediction models for the risk of total knee replacement: development and validation using data from multicentre cohort studies.

Few prognostic prediction models for total knee replacement are available, and the role of radiographic findings in predicting its use remains unclear. We aimed to develop and validate predictive models for total knee replacement and to assess whether adding radiographic findings improves predictive performance. We identified participants with recent knee pain (in the past 3 months) in the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI). The baseline visits of MOST were initiated in 2003 and of OAI were initiated in 2004. We developed two predictive models for the risk of total knee replacement within 60 months of follow-up by fitting Cox proportional hazard models among participants in MOST. The first model included sociodemographic and anthropometric factors, medical history, and clinical measures (referred to as the clinical model). The second model added radiographic findings into the predictive model (the radiographic model). We evaluated each model's discrimination and calibration performance and assessed the incremental value of radiographic findings using both category-free net reclassification improvement (NRI) and integrated discrimination improvement (IDI). We tuned the models and externally validated them among participants in OAI. We included 2658 participants from MOST (mean age 62·4 years [SD 8·1], 1646 [61·9%] women) in the training dataset and 4060 participants from OAI (mean age 60·9 years [9·1], 2379 [58·6%] women) in the validation dataset. 290 (10·9%) participants in the training dataset and 174 (4·3%) in the validation dataset had total knee replacement. The retained predictive variables included in the clinical model were age, sex, race, history of knee arthroscopy, frequent knee pain, current use of analgesics, current use of glucosamine, body-mass index, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score, and the most predictive factors were age, race, and WOMAC pain score. The retained predictive variables in the radiographic model were age, sex, race, frequent knee pain, current use of analgesics, WOMAC pain score, and Kellgren-Lawrence grade, and the most predictive factors were Kellgren-Lawrence grade, race, and age. The C-statistic was 0·79 (95% CI 0·76-0·81) for the clinical model and 0·87 (0·85-0·99) for the radiographic model in the training dataset. The calibration slope was 0·95 (95% CI 0·86-1·05) and 0·96 (0·87-1·04), respectively. Adding radiograph findings significantly improved predictive performance with an NRI of 0·43 (95% CI 0·38-0·50) and IDI of 0·14 (95% CI: 0·10-0·18). Both models, with tuned coefficients, showed a good predictive performance among participants in the validation dataset. The risk of total knee replacement can be predicted based on common risk factors with good discrimination and calibration. Additionally, adding radiographic findings of knee osteoarthritis into the model substantially improves its predictive performance. National Natural Science Foundation of China, National Key Research and Development Program, and Beijing Municipal Science & Technology Commission.

Risk of total knee replacement after proximal tibia fracture: a register-based study of 7,841 patients.

Background and purposePost-traumatic knee osteoarthritis following proximal tibia fracture (PTF) is a common complication that may lead to total knee replacement as secondary treatment (TKRS). We determined the risk of TKRS following PTF, whether treated nonoperatively or operatively, and compared the results with a 38-fold control group without prior PTF.Patients and methodsWe identified all patients over 18 years of age in Finland with PTF treated during the period 2009–2018 from the Finnish Hospital Discharge Register (FHDR) and Finnish Arthroplasty Register (FAR). Age, sex, treatment method, follow-up time, and possible TKRS were recorded.Results7,701 patients were treated for PTF during the period 2009–2018. Over the 5.1-year (SD 3.1) follow-up, TKRS was performed in 340 (4.3%) patients with a prior PTF after a mean of 2.1 (SD 2.0) years post-fracture. TKRS was needed in 138 (3.7%, HR 1.8) patients in the nonoperatively treated group and in 202 (5.0%, HR 3.2) patients in the operatively treated group. Operative treatment, female sex, and high age were identified as risk factors for TKRS. The incidence of TKRS was highest during the first 2 years after fracture and remained elevated throughout the follow-up.InterpretationPatients with a prior PTF had a 1.8- to 3.2-fold higher risk of TKRS compared with controls during the first 5 years post-fracture. Risk of TKRS was associated with an operatively treated PTF, female sex, and high age. The patients in the operative group likely sustained more complex fractures, while female sex and age may be explained by more osteoporotic bone quality.

The burden of end-stage osteoarthritis in Australia: a population-based study on the incidence of total knee replacement attributable to overweight/obesity

To determine the risk of total knee replacement (TKR) for primary osteoarthritis (OA) associated with overweight/obesity in the Australian population. This population-based study analyzed 191,723 cases of TKR collected by the Australian Orthopaedic Association National Joint Registry and population data from the Australian Bureau of Statistics. The time-trend change in incidence of TKR relating to BMI was assessed between 2015 and 2018. The influence of obesity on the incidence of TKR in different age and gender groups was determined. The population attributable fraction (PAF) was then calculated to estimate the effect of obesity reduction on TKR incidence. The greatest increase in incidence of TKR was seen in patients from obese class III. The incidence rate ratio for having a TKR for obesity class III was 28.683at those aged 18-54 years but was 2.029at those aged >75 years. Females in obesity class III were 1.7 times more likely to undergo TKR compared to similarly classified males. The PAFs of TKR associated with overweight or obesity was 35%, estimating 14,287 cases of TKR attributable to obesity in 2018. The proportion of TKRs could be reduced by 20% if overweight and obese population move down one category. Obesity has resulted in a significant increase in the incidence of TKR in the youngest population in Australia. The impact of obesity is greatest in the young and the female population. Effective strategies to reduce the national obese population could potentially reduce 35% of the TKR, with over 10,000 cases being avoided.

Irregular types of proximal tibiofibular joint increase the risk of total knee replacement: Data from the osteoarthritis initiative.

The study aimed to determine the associations between the morphological types of proximal tibiofibular joint (PTFJ) and the risk of total knee replacement (TKR) in a cohort of participants with progressive osteoarthritis. A nested case-control design was performed in Osteoarthritis Initiative study. The case knees were those with TKR at 24-60 months follow up (cases), and were 1:1 matched with control knees by age, sex, and Kellgren-Lawrence grade at baseline. The morphological type of each PTFJ was identified according to the coronal and sagittal MR images. Conditional logistic regression models were used to examine the association of the PTFJ types with the risk of TKR at baseline and the time point before TKR (T0 ). A total of 193 case knees at baseline and 148 case knees at T0 time point had matched controls between 12 and 60 M. Seven types of the PTFJ were identified and classified into three categories: plane, trochoid, and irregular types. The prevalence of the irregular type was higher in case knees than in controls both at baseline (cases vs. controls, 35.8% vs. 26.9%) and at T0 time point (cases vs. controls, 33.1% vs. 27.0%). The irregular type of the PTFJ at baseline (odds ratio: 1.62, 95% confidence interval: 1.01-2.59) rather than at T0 time point was significantly associated with increased odds of TKR. The irregular types of the PTFJ at baseline are associated with increased risk of TKR, suggesting PTFJ may play a role in knee osteoarthritis.

Unicompartmental compared with total knee replacement for patients with multimorbidities: a cohort study using propensity score stratification and inverse probability weighting.

Although routine NHS data potentially include all patients, confounding limits their use for causal inference. Methods to minimise confounding in observational studies of implantable devices are required to enable the evaluation of patients with severe systemic morbidity who are excluded from many randomised controlled trials. Stage 1 - replicate the Total or Partial Knee Arthroplasty Trial (TOPKAT), a surgical randomised controlled trial comparing unicompartmental knee replacement with total knee replacement using propensity score and instrumental variable methods. Stage 2 - compare the risk benefits and cost-effectiveness of unicompartmental knee replacement with total knee replacement surgery in patients with severe systemic morbidity who would have been ineligible for TOPKAT using the validated methods from stage 1. This was a cohort study. Data were obtained from the National Joint Registry database and linked to hospital inpatient (Hospital Episode Statistics) and patient-reported outcome data. Stage 1 - people undergoing unicompartmental knee replacement surgery or total knee replacement surgery who met the TOPKAT eligibility criteria. Stage 2 - participants with an American Society of Anesthesiologists grade of ≥ 3. The patients were exposed to either unicompartmental knee replacement surgery or total knee replacement surgery. The primary outcome measure was the postoperative Oxford Knee Score. The secondary outcome measures were 90-day postoperative complications (venous thromboembolism, myocardial infarction and prosthetic joint infection) and 5-year revision risk and mortality. The main outcome measures for the health economic analysis were health-related quality of life (EuroQol-5 Dimensions) and NHS hospital costs. In stage 1, propensity score stratification and inverse probability weighting replicated the results of TOPKAT. Propensity score adjustment, propensity score matching and instrumental variables did not. Stage 2 included 2256 unicompartmental knee replacement patients and 57,682 total knee replacement patients who had severe comorbidities, of whom 145 and 23,344 had linked Oxford Knee Scores, respectively. A statistically significant but clinically irrelevant difference favouring unicompartmental knee replacement was observed, with a mean postoperative Oxford Knee Score difference of < 2 points using propensity score stratification; no significant difference was observed using inverse probability weighting. Unicompartmental knee replacement more than halved the risk of venous thromboembolism [relative risk 0.33 (95% confidence interval 0.15 to 0.74) using propensity score stratification; relative risk 0.39 (95% confidence interval 0.16 to 0.96) using inverse probability weighting]. Unicompartmental knee replacement was not associated with myocardial infarction or prosthetic joint infection using either method. In the long term, unicompartmental knee replacement had double the revision risk of total knee replacement [hazard ratio 2.70 (95% confidence interval 2.15 to 3.38) using propensity score stratification; hazard ratio 2.60 (95% confidence interval 1.94 to 3.47) using inverse probability weighting], but half of the mortality [hazard ratio 0.52 (95% confidence interval 0.36 to 0.74) using propensity score stratification; insignificant effect using inverse probability weighting]. Unicompartmental knee replacement had lower costs and higher quality-adjusted life-year gains than total knee replacement for stage 2 participants. Although some propensity score methods successfully replicated TOPKAT, unresolved confounding may have affected stage 2. Missing Oxford Knee Scores may have led to information bias. Propensity score stratification and inverse probability weighting successfully replicated TOPKAT, implying that some (but not all) propensity score methods can be used to evaluate surgical innovations and implantable medical devices using routine NHS data. Unicompartmental knee replacement was safer and more cost-effective than total knee replacement for patients with severe comorbidity and should be considered the first option for suitable patients. Further research is required to understand the performance of propensity score methods for evaluating surgical innovations and implantable devices. This trial is registered as EUPAS17435. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 66. See the NIHR Journals Library website for further project information.

Effects of Sarcopenic Obesity and Its Confounders on Knee Range of Motion Outcome after Total Knee Replacement in Older Adults with Knee Osteoarthritis: A Retrospective Study.

Sarcopenic obesity is closely associated with knee osteoarthritis (KOA) and has high risk of total knee replacement (TKR). In addition, poor nutrition status may lead to sarcopenia and physical frailty in KOA and is negatively associated with surgery outcome after TKR. This study investigated the effects of sarcopenic obesity and its confounding factors on recovery in range of motion (ROM) after total knee replacement (TKR) in older adults with KOA. A total of 587 older adults, aged ≥60 years, who had a diagnosis of KOA and underwent TKR, were enrolled in this retrospective cohort study. Sarcopenia and obesity were defined based on cutoff values of appendicular mass index and body mass index for Asian people. Based on the sarcopenia and obesity definitions, patients were classified into three body-composition groups before TKR: sarcopenic-obese, obese, and non-obese. All patients were asked to attend postoperative outpatient follow-up admissions. Knee flexion ROM was measured before and after surgery. A ROM cutoff of 125 degrees was used to identify poor recovery post-surgery. Kaplan-Meier curve analysis was performed to measure the probability of poor ROM recovery among study groups. Cox multivariate regression models were established to calculate the hazard ratios (HRs) of postoperative poor ROM recovery, using potential confounding factors including age, sex, comorbidity, risk of malnutrition, preoperative ROM, and outpatient follow-up duration as covariates. Analyses results showed that patients in the obese and sarcopenic-obese groups had a higher probability of poor ROM recovery compared to the non-obese group (all p < 0.001). Among all body-composition groups, the sarcopenic-obese group yielded the highest risk of postoperative physical difficulty (adjusted HR = 1.63, p = 0.03), independent to the potential confounding factors. Sarcopenic obesity is likely at the high risk of poor ROM outcome following TKR in older individuals with KOA.

Effects of biologics on reducing the risks of total knee replacement and total hip replacement in rheumatoid arthritis.

RA damages the joints and increases the risks of total knee replacement (TKR) and total hip replacement (THR). However, the benefits of biologics in preventing TKR or THR remain unclear. This retrospective nationwide study used the 2000-2013 claims-based National Health Insurance dataset. Biologics are reimbursed for refractory cases. The risks of TKR and THR in the biologic cohort were compared with those of an age- and sex-matched csDMARD cohort. A multivariate Cox regression model was used to investigate the benefits of bDMARDs for TKR and THR. TKR was performed in 5979 biologic cases and 11 958 matched controls, of which 249 (4.16%) and 871 (7.28%) cases received TKR, respectively. THR was performed in 6245 biologic cases and 12 490 matched controls, of which 159 (2.55%) and 516 (4.13%) cases had THR, respectively. The biologic cohort had significantly lower incidence rates of TKR (11.73 vs 16.33/1000 person-years, P < 0.001) and THR (7.09 vs 9.16/1000 person-years, P < 0.001). After adjustment for confounding factors, the regular bDMARD subgroup (average dose >0.95 defined daily dose/day) had significantly lower risks of TKR (aHR: 0.55, 95% CI: 0.38, 0.81) and THR (aHR: 0.63, 95% CI: 0.40, 0.98). Those without MTX use, with steroid use, with biologic switch, and overlapping antiphospholipid syndrome had significantly higher risks of TKR and THR. Compared with the csDMARD cohort, the risks of TKR and THR in the bDMARD cohort were the same as those in the low-to-moderate dose subgroups and significantly lower in those with regular bDMARD use.

Metformin use and the risk of total knee replacement among diabetic patients in primary care

Purpose: Metformin, apart from its glucose lowering and weight reduction effects, has recently been shown to modulate meta-inflammation, an important pathogenesis in knee osteoarthritis (OA). We aim to study the association between regular metformin use and total knee replacement (TKR) in primary care patients with diabetes.

Food sources of dietary fibre and risk of total knee replacement related to severe osteoarthritis, the Singapore Chinese Health Study

ObjectivesWe aimed to evaluate the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe knee osteoarthritis (KOA).MethodsWe used data from...

Increased Incidence of Total Knee Replacement Surgery in Patients With Psoriasis: A Secondary Cohort Analysis of a Nationwide, Population-Based Health Claims Database.

Patients with rheumatic diseases, such as rheumatoid arthritis, ankylosing spondylitis, and systemic lupus erythematosus, have increased risk of receiving total knee replacement surgery or total hip replacement surgery. We speculated that psoriasis could also attack the joints of the knees and hips, leading to an increased risk of receiving total knee replacement surgery or total hip replacement surgery. The aim of this study was to investigate the risk of total knee replacement or total hip replacement surgery in patients with psoriasis using a nationwide, population-based health claims database in Taiwan. Using the Taiwan's National Health Insurance Research Database, we identified 10,819 patients with psoriasis between 2000 and 2012. A comparison cohort consisting of five patients without psoriasis for each patient with psoriasis was assembled, based on frequency matching for sex, 10-year age interval, and index year. Both groups were followed until a diagnosis of the study outcomes (total knee replacement or total hip replacement surgery) or the end of the follow-up period. Incidence rate ratios (IRRs) for the outcome variables were calculated using multiple Poisson regression models. Female patients with psoriasis exhibited a significantly higher incidence of receiving total knee replacement surgery [adjusted IRR = 1.44, p = 0.014)]. Analyses stratified by age groups showed that the risk of receiving total knee replacement surgery was significantly higher older (adjusted IRR = 1.31, p = 0.047) patients with psoriasis. There were no significant differences in the risk of receiving total hip replacement surgery in patients with psoriasis compared with controls, either with or without stratification by sex or age groups. In conclusion, patients with psoriasis were associated with an increased risk of receiving total knee. Clinicians should be vigilant in assessing the presence of arthritis in these patients, and initiate strategies to delay or prevent the need for joint replacement.

Predictive value of the morphology of proximal tibiofibular joint for total knee replacement in patients with knee osteoarthritis.

The association between proximal tibiofibular joint (PTFJ) and knee osteoarthritis (OA) has been understudied. The objective of this study was to determine whether the morphology of PTFJ has predictive value for the risk of total knee replacement (TKR). Case knees from Osteoarthritis Initiative participants with TKR at 24-60 months follow up (cases) were 1:1 matched with control knees (no TKR throughout 60 months) by baseline age, sex, and Kellgren-Lawrence grade. PTFJ morphological parameters, including coronal inclination angle (angle α), sagittal inclination angle (angle β), fibular contacting area (S), load-bearing area (Sτ), lateral stress-bolstering area (Sφ), and posterior stress-bolstering area (Sυ) were assessed using coronal and sagittal magnetic resonance imaging (MRI), respectively. Associations of the morphological measures at baseline and the time point before TKR (T0 ) and their changes with TKR risks were examined using conditional logistic regression analyses. Two hundred and twenty-three knees of 193 participants received TKR between 12 and 60 months and therefore were matched with 223 control knees. Of these, 173 paired knees had MRI readings available both at baseline and T0 time point. While baseline angle α was positively associated with TKR risk, other measures at baseline and all measures at T0 were not significantly associated with TKR risk. Changes in S, Sτ, and Sυ were significantly and negatively associated with the risk of TKR (ΔS, odds ratio [OR] = 0.38, 95% confidence interval [CI]: 0.19-0.76; ΔSτ, OR = 0.37, 95% CI: 0.16-0.87; ΔSυ, OR = 0.22, 95% CI: 0.08-0.62, respectively). This data shows that morphological changes of PTFJ predict the risk of TKR, suggesting PTFJ may play a role in knee OA.